2.A Chronic Psoriasis Model Using Long-Term Imiquimod Application in IL-10-Deficient Mice: Recapitulating Skin Inflammation, Comorbidities, and Gut–Skin Axis Alterations
Jee Hyun KIM ; Soo Ran LEE ; Hyun Keun AHN ; Hyun Taek HONG ; Ui Hyeon JO ; Jong Pil IM ; Joo Sung KIM ; Min Jung KIM ; Jeonghwan LEE ; Jeong Hwan PARK ; Hyunsun PARK ; Seong-joon KOH
Annals of Dermatology 2025;37(6):383-396
Background:
Psoriasis is a persistent systemic inflammatory condition mediated by the interleukin (IL)-23/IL-17 signaling pathway. Existing murine models, including imiquimod (IMQ)-applied wild-type (WT) mice, may not reflect chronicity and systemic comorbidities of psoriasis, particularly gut-related manifestations linked to the gut–skin axis.
Objective:
To establish a murine model that more accurately reflects chronic psoriasis, its systemic comorbidities, and associated gut environment alterations.
Methods:
C57BL/6 IL-10-deficient (IL-10 knockout [KO]) and WT mice received topical IMQ or vehicle for 6 weeks. Subsequently, tissue samples from skin, colon, joints, kidneys, liver, abdominal aortas, lymph nodes, and spleens, as well as fecal and blood samples, were collected for histopathologic, immunologic, gut environment analysis.
Results:
IMQ-treated IL-10 KO mice developed prolonged psoriatic inflammatory responses with increased epidermal thickness and higher infiltration of CD45+, myeloperoxidase+, and IL-17+ cells. They also exhibited early-onset, severe colitis with marked weight loss, shortened colon length, and elevated colitis severity scores. While IMQ induced systemic inflammation in multiple organs, IL-10 KO mice did not show more severe joint, liver, or kidney involvement than WT mice. Elevated serum tumor necrosis factor alpha and plasminogen activator inhibitor-1 levels, increased heart/body weight ratio, enhanced gut permeability, and distinct gut microbiota profiles were observed in IL-10 KO mice.
Conclusion
The 6-week IMQ-applied IL-10 KO model may better reflect chronic and severe psoriasis with gut-related comorbidities, offering a valuable platform to investigate the gut–skin axis.
3.Polyunsaturated Fatty Acids and Skin Cancer: Two-Sample Mendelian Randomization Study
Gahyun KIM ; Bo Ri KIM ; Kyungho PAIK ; Seon-Pil JIN ; Hyunsun PARK ; Woojae MYUNG ; Jin-Ku LEE ; Chong Won CHOI ; Jinho KIM
Annals of Dermatology 2025;37(6):363-376
Background:
Observational studies have suggested associations between dietary polyunsaturated fatty acids (PUFAs) and cancer risk; however, causal inference regarding skin cancer remains limited due to potential recall bias, confounding, and reverse causation.
Objective:
This study aimed to evaluate the causal association between genetically predicted circulating PUFA levels and the risk of skin cancers, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma.
Methods:
We conducted a 2-sample Mendelian randomization (MR) study using genome-wide association study summary statistics from the UK Biobank (PUFAs, n=115,006) and the FinnGen consortium (BCC, n=26,272; SCC, n=4,663; melanoma, n=5,753). Genetic instruments were derived for omega-3, docosahexaenoic acid, omega-6, linoleic acid, and the omega-6:3 ratio.Multiple MR methods—including inverse-variance weighted, MR-Egger, weighted median, weighted mode, and MR-PRESSO—were applied to test for consistency and assess pleiotropy and heterogeneity.
Results:
A higher genetically predicted linoleic acid to total fatty acid ratio was associated with a significantly lower risk of BCC and SCC. Conversely, higher genetically proxied serum omega-3 levels were associated with increased risks of BCC, SCC, and melanoma. The risk effect on SCC was attenuated upon exclusion of rs174528, a variant in the fatty acid desaturase 1 (FADS1) gene, suggesting a role for endogenous PUFA metabolism in carcinogenesis.
Conclusion
This MR analysis supports a causal role of circulating PUFAs in skin cancer development and highlights the importance of FADS-mediated endogenous PUFA metabolism. These findings provide novel insights into the genetic and metabolic underpinnings of skin cancer susceptibility.
4.Evaluation of N95 Respirator Fit Changes in Nurses Working in High-risk Airborne Infection Units
Si-Hyeon HAN ; Kyung-Sook CHA ; Hyunsun LEE ; Yeonhee CHOUNG
Korean Journal of healthcare-associated Infection Control and Prevention 2024;29(2):137-145
Background:
Healthcare workers (HCWs) face an increased risk of airborne infections owing to close patient contact and extended shifts. N95 respirators require routine fit testing to ensure effective protection. This study assessed the fit stability of N95 masks among nurses working in airborne infection units, using annual fit tests to observe changes over time.
Methods:
From May 2020 to January 2023, 37 nurses from the high-risk airborne infection units of a university hospital participated in this study. The fit tests followed the Occupational Safety and Health Administration’s Quantitative Fit Testing protocol, and non-parametric statistical analyses were applied. Nurses received formal annual training on N95 mask use and individualized guidance before each fit test.
Results:
In the initial test, 46.0% passed; of these, 15 consistently passed the second test (Group 1, Pass-Pass) and 2 failed (Group 2, Pass-Fail). No significant associations were found between demographic or job factors and the fit test outcomes. Average fit scores decreased from 100.79 (±58.22) initially to 32.25 (±66.54) in the second test, showing variability.
Conclusion
Ongoing training and experience improved fit consistency over time, emphasizing the importance of regular education. Rather than testing annually, targeted testing when selecting a new respirator or performing subsequent facial changes may enhance the protection of HCWs and reduce costs.
5.Impact of COVID-19 Infection and Related Social Concerns on Depressive Symptoms: Mediating Effects of Negative Changes in Daily Life and Moderating Effects of Age and Gender
Dham HO ; Sun-Young KIM ; Hye Ah LEE ; Hyunsun CHO ; Weon-Jeong LIM
Psychiatry Investigation 2024;21(12):1318-1328
Objective:
This study examined the mediating effect of negative changes in daily life due to the coronavirus disease-2019 (COVID-19) pandemic on depressive symptoms, considering COVID-19 infection and related social concerns. Additionally, comparisons of path coefficients between the groups were conducted based on age and gender.
Methods:
A cross-sectional study design used data from the 2020 Korean Community Health Survey consisting of 229,269 individuals. This study used a self-reported questionnaire, including the Patient Health Questionnaire-9 and three items addressing social concerns related to COVID-19 infection. A single question assessed whether individuals had experienced COVID-19 infection within the last 3 months, and scores of negative changes in daily life due to the COVID-19 pandemic. Correlation analysis was performed on the variables. Structural equation model analysis was conducted to identify the mediating role of negative changes in daily life. Chi-square tests were also performed to compare the path coefficients based on age and gender.
Results:
The structural equation models revealed that COVID-19 infection and related social concerns had both significant direct effects on depressive symptoms and indirect effects through negative changes in daily life. When comparing the path coefficients by age and gender, the coefficients related to depressive symptoms were highest in those under 65 years and in females.
Conclusion
Negative changes in daily life due to the COVID-19 pandemic serve as a partial mediator of the impact of COVID-19 infection and related social concerns on depressive symptoms. Special attention should be paid to depressive symptoms in those under 65 years of age and in females.
6.Impact of COVID-19 Infection and Related Social Concerns on Depressive Symptoms: Mediating Effects of Negative Changes in Daily Life and Moderating Effects of Age and Gender
Dham HO ; Sun-Young KIM ; Hye Ah LEE ; Hyunsun CHO ; Weon-Jeong LIM
Psychiatry Investigation 2024;21(12):1318-1328
Objective:
This study examined the mediating effect of negative changes in daily life due to the coronavirus disease-2019 (COVID-19) pandemic on depressive symptoms, considering COVID-19 infection and related social concerns. Additionally, comparisons of path coefficients between the groups were conducted based on age and gender.
Methods:
A cross-sectional study design used data from the 2020 Korean Community Health Survey consisting of 229,269 individuals. This study used a self-reported questionnaire, including the Patient Health Questionnaire-9 and three items addressing social concerns related to COVID-19 infection. A single question assessed whether individuals had experienced COVID-19 infection within the last 3 months, and scores of negative changes in daily life due to the COVID-19 pandemic. Correlation analysis was performed on the variables. Structural equation model analysis was conducted to identify the mediating role of negative changes in daily life. Chi-square tests were also performed to compare the path coefficients based on age and gender.
Results:
The structural equation models revealed that COVID-19 infection and related social concerns had both significant direct effects on depressive symptoms and indirect effects through negative changes in daily life. When comparing the path coefficients by age and gender, the coefficients related to depressive symptoms were highest in those under 65 years and in females.
Conclusion
Negative changes in daily life due to the COVID-19 pandemic serve as a partial mediator of the impact of COVID-19 infection and related social concerns on depressive symptoms. Special attention should be paid to depressive symptoms in those under 65 years of age and in females.
7.Evaluation of N95 Respirator Fit Changes in Nurses Working in High-risk Airborne Infection Units
Si-Hyeon HAN ; Kyung-Sook CHA ; Hyunsun LEE ; Yeonhee CHOUNG
Korean Journal of healthcare-associated Infection Control and Prevention 2024;29(2):137-145
Background:
Healthcare workers (HCWs) face an increased risk of airborne infections owing to close patient contact and extended shifts. N95 respirators require routine fit testing to ensure effective protection. This study assessed the fit stability of N95 masks among nurses working in airborne infection units, using annual fit tests to observe changes over time.
Methods:
From May 2020 to January 2023, 37 nurses from the high-risk airborne infection units of a university hospital participated in this study. The fit tests followed the Occupational Safety and Health Administration’s Quantitative Fit Testing protocol, and non-parametric statistical analyses were applied. Nurses received formal annual training on N95 mask use and individualized guidance before each fit test.
Results:
In the initial test, 46.0% passed; of these, 15 consistently passed the second test (Group 1, Pass-Pass) and 2 failed (Group 2, Pass-Fail). No significant associations were found between demographic or job factors and the fit test outcomes. Average fit scores decreased from 100.79 (±58.22) initially to 32.25 (±66.54) in the second test, showing variability.
Conclusion
Ongoing training and experience improved fit consistency over time, emphasizing the importance of regular education. Rather than testing annually, targeted testing when selecting a new respirator or performing subsequent facial changes may enhance the protection of HCWs and reduce costs.
8.Impact of COVID-19 Infection and Related Social Concerns on Depressive Symptoms: Mediating Effects of Negative Changes in Daily Life and Moderating Effects of Age and Gender
Dham HO ; Sun-Young KIM ; Hye Ah LEE ; Hyunsun CHO ; Weon-Jeong LIM
Psychiatry Investigation 2024;21(12):1318-1328
Objective:
This study examined the mediating effect of negative changes in daily life due to the coronavirus disease-2019 (COVID-19) pandemic on depressive symptoms, considering COVID-19 infection and related social concerns. Additionally, comparisons of path coefficients between the groups were conducted based on age and gender.
Methods:
A cross-sectional study design used data from the 2020 Korean Community Health Survey consisting of 229,269 individuals. This study used a self-reported questionnaire, including the Patient Health Questionnaire-9 and three items addressing social concerns related to COVID-19 infection. A single question assessed whether individuals had experienced COVID-19 infection within the last 3 months, and scores of negative changes in daily life due to the COVID-19 pandemic. Correlation analysis was performed on the variables. Structural equation model analysis was conducted to identify the mediating role of negative changes in daily life. Chi-square tests were also performed to compare the path coefficients based on age and gender.
Results:
The structural equation models revealed that COVID-19 infection and related social concerns had both significant direct effects on depressive symptoms and indirect effects through negative changes in daily life. When comparing the path coefficients by age and gender, the coefficients related to depressive symptoms were highest in those under 65 years and in females.
Conclusion
Negative changes in daily life due to the COVID-19 pandemic serve as a partial mediator of the impact of COVID-19 infection and related social concerns on depressive symptoms. Special attention should be paid to depressive symptoms in those under 65 years of age and in females.
9.Impact of COVID-19 Infection and Related Social Concerns on Depressive Symptoms: Mediating Effects of Negative Changes in Daily Life and Moderating Effects of Age and Gender
Dham HO ; Sun-Young KIM ; Hye Ah LEE ; Hyunsun CHO ; Weon-Jeong LIM
Psychiatry Investigation 2024;21(12):1318-1328
Objective:
This study examined the mediating effect of negative changes in daily life due to the coronavirus disease-2019 (COVID-19) pandemic on depressive symptoms, considering COVID-19 infection and related social concerns. Additionally, comparisons of path coefficients between the groups were conducted based on age and gender.
Methods:
A cross-sectional study design used data from the 2020 Korean Community Health Survey consisting of 229,269 individuals. This study used a self-reported questionnaire, including the Patient Health Questionnaire-9 and three items addressing social concerns related to COVID-19 infection. A single question assessed whether individuals had experienced COVID-19 infection within the last 3 months, and scores of negative changes in daily life due to the COVID-19 pandemic. Correlation analysis was performed on the variables. Structural equation model analysis was conducted to identify the mediating role of negative changes in daily life. Chi-square tests were also performed to compare the path coefficients based on age and gender.
Results:
The structural equation models revealed that COVID-19 infection and related social concerns had both significant direct effects on depressive symptoms and indirect effects through negative changes in daily life. When comparing the path coefficients by age and gender, the coefficients related to depressive symptoms were highest in those under 65 years and in females.
Conclusion
Negative changes in daily life due to the COVID-19 pandemic serve as a partial mediator of the impact of COVID-19 infection and related social concerns on depressive symptoms. Special attention should be paid to depressive symptoms in those under 65 years of age and in females.
10.Evaluation of N95 Respirator Fit Changes in Nurses Working in High-risk Airborne Infection Units
Si-Hyeon HAN ; Kyung-Sook CHA ; Hyunsun LEE ; Yeonhee CHOUNG
Korean Journal of healthcare-associated Infection Control and Prevention 2024;29(2):137-145
Background:
Healthcare workers (HCWs) face an increased risk of airborne infections owing to close patient contact and extended shifts. N95 respirators require routine fit testing to ensure effective protection. This study assessed the fit stability of N95 masks among nurses working in airborne infection units, using annual fit tests to observe changes over time.
Methods:
From May 2020 to January 2023, 37 nurses from the high-risk airborne infection units of a university hospital participated in this study. The fit tests followed the Occupational Safety and Health Administration’s Quantitative Fit Testing protocol, and non-parametric statistical analyses were applied. Nurses received formal annual training on N95 mask use and individualized guidance before each fit test.
Results:
In the initial test, 46.0% passed; of these, 15 consistently passed the second test (Group 1, Pass-Pass) and 2 failed (Group 2, Pass-Fail). No significant associations were found between demographic or job factors and the fit test outcomes. Average fit scores decreased from 100.79 (±58.22) initially to 32.25 (±66.54) in the second test, showing variability.
Conclusion
Ongoing training and experience improved fit consistency over time, emphasizing the importance of regular education. Rather than testing annually, targeted testing when selecting a new respirator or performing subsequent facial changes may enhance the protection of HCWs and reduce costs.

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